There are many different machines currently available that may be used to fill a container such as a bottle containing a beverage. Such machines operate using a variety of different principles. These principles depend on a number of factors such as the nature of the liquid and the scale of the filling operation.
Filling containers such as bottles with carbonated beverages such as beer or carbonated soft drinks can present some particular challenges. During the filling process, the carbonated beverage can foam and can lose some of its carbonation. Loss of carbonation can leave the beverage “flat” and excess foaming can also cause wastage and spillage that needs to be cleaned up.
One aim of most currently available machines is to minimise agitation of the carbonated liquid during the filling process, to reduce foaming and decarbonation of the liquid. This is usually achieved by having a relatively slow fill speed (although chilling the carbonated liquid may also help minimise excess foaming).
Currently used filling techniques generally involve the use of a filler machine that has a header tank of the liquid above the bottle. This header tank is pressurised with carbon dioxide. A bottle to be filled is sealed onto a filler head of the filler machine and the bottle is normally then evacuated and/or gas purged to remove oxygen. Next the bottle is filled with carbon dioxide to the same pressure as the header tank above. The bottle is filled using gravity. To avoid excessive foaming and therefore decarbonation of the beverage, this process is carried out relatively slowly. For example, a fill time of at least 15 to 20 seconds would be within normal bounds.
Alternatively, some hand operated machines bleed the gas out of the bottle so the liquid can flow into the bottle. The bottle is then vented and sent to a capper. These hand operated machines also provide only relatively slow filling speeds.
Counter-pressure bottle fillers are well known in the art and can help to reduce foaming and decarbonation. In use, a counter-pressure bottle filler is connected to a container of carbonated beverage and to a carbon dioxide tank. The counter-pressure bottle filler is inserted into a bottle to be filled. The opening of the bottle is then secured with a stopper and a valve to the carbon dioxide tank is opened to allow carbon dioxide to fill the bottle. A bleed valve is opened to allow air to escape. The bleed valve is then closed, allowing the bottle to be pressurised to the same pressure as the container of carbonated beverage. The valve to the carbon dioxide tank is closed and a valve to the container of carbonated beverage is opened. As the pressure in the bottle is the same as the pressure in the container of carbonated beverage, the beverage will not flow into the bottle. Flow is achieved by opening the bleed valve slightly. This gradually reduces the pressure in the bottle and the beverage will slowly fill the bottle.
This arrangement has several drawbacks. The procedure involves a number of steps that must be carried out in the correct order to avoid excessive foaming and/or oxidation of the beverage, or excessive spraying of the beverage from the bottle. This arrangement also provides for only relatively slow filling of the bottle.
U.S. Pat. No. 7,730,912 describes a bottle filler that provides an alternative to counter-pressure bottle fillers. The bottle filler of U.S. Pat. No. 7,730,912 is designed to reduce oxidation of a carbonated beverage as it is bottled. A long hose is provided, which gradually reduces the pressure of the beverage on the way to the filler. A valve seat is located at the bottom of a filling tube to allow the carbonated beverage to flow into the bottle from the bottom of the bottle. Two filling tubes are placed one inside the other to form an annulus that allows carbon dioxide to be forced into the bottom of the bottle to purge the bottle of air prior to filling. A disadvantage of the bottle filler of U.S. Pat. No. 7,730,912 however is that it provides a relatively slow fill rate and does not allow for accurate measurement of volume.
Another aim when filling bottles is to accurately fill each bottle with a predetermined volume of beverage. This is to reduce or minimise wastage, and to ensure consumers receive the stated volume of beverage purchased. Currently used filling techniques do not always provide accurate fill levels.
There is an ongoing need for filler machines and methods that allow more efficient and/or accurate filling of containers such as bottles. There is a further ongoing need to provide a filler machine and method that at least provides a useful alternative to known filler machines and methods.
References to any external documents in this specification are for the purpose of providing a context for discussing the present invention. Such references are not, and should not be taken as, an acknowledgement or any form of suggestion that the documents are prior art or form part of the common general knowledge.